2007 Ram 2500 (Diesel) Owner's Manual

Defrost
Outside air is primarily directed to the windshield
through the defroster outlets located at the base of
the windshield and side window demist outlets.
NOTE:The air conditioning compressor operates in
both Mix and Defrost or a blend of these modes, even if
the A/C button has not been pressed. This dehumidifies
the air to help dry the windshield.
Blower Control
The rotary knob on the left of the
control panel is the blower control.
Turn the knob clockwise to one of the
four positions to obtain the blower
speed you desire. To turn the blower
off, turn the knob to the far left posi-
tion.
Dual Zone Temperature Control
Use this control to regulate the temperature of the air
inside the passenger compartment. This is accomplished
by having separate temperature control slides for both
the driver and front passenger. The blue area of the scale
indicates cooler temperatures while the red area indicates
warmer temperatures.
Dual Zone Temperature Control
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4

Circulation
The cab is designed with features to promote outside air
circulation. There are grilles in the cab back panel. These
are air exhausters that provide the means for regular
exchange of cab air.
Side window demisters direct air flow specifically to the
window glass to help prevent interior fogging of the
glass. They are located in the extreme outside upper
edges of the instrument panel. The demisters also pro-
vide extra air ducts for circulation. They are in operation
whenever the Floor, Mix or Defrost modes are in use.
NOTE:When you turn off the engine you may hear a
hissing sound from under the hood for a short period of
time. This is a normal condition that occurs if the air
conditioning system has been on. It is not an indication of
a problem with the air conditioning system.
Rear Air Duct—Mega Cab Only
The rear seat will receive air flow in all modes except for
Defrost.
The rear air duct is designed to be pointed up when in
A/C mode, and pointed down in Heat mode.
Mega Cab Rear Air Duct
266 UNDERSTANDING YOUR INSTRUMENT PANEL

Operating Tips
Fast Cooldown
For a fast cooldown, turn the blower fan rotary knob to
the extreme right position, turn the mode control to the
panel fresh position, press the snowflake button to turn
on the air conditioning, and drive with the windows
open for the first few minutes. Once the hot air has been
expelled, close the windows and press the Recirculation
push-button. When a comfortable condition has been
reached, choose a mode position and adjust the tempera-
ture control slide and blower speed as necessary to
maintain comfort. For high humidity conditions it may
be necessary to remain in the Recirculation mode to
maintain comfort.
Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cooltemperatures when it’s rainy or humid. In most cases
turning on the Air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield by using MIX Mode
position on the control. Adjust the temperature control
and blower speed to maintain comfort. Higher blower
speeds will reduce fogging. Interior fogging on the
windshield can be quickly removed by selecting the
defrost mode.
Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette
smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
UNDERSTANDING YOUR INSTRUMENT PANEL 267
4

Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Recommended
Fluids and Genuine Parts for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
268 UNDERSTANDING YOUR INSTRUMENT PANEL

Operating Tips Chart
UNDERSTANDING YOUR INSTRUMENT PANEL 269
4

STARTING AND OPERATING
CONTENTS

Starting Procedures – Diesel Engines.........275
▫Manual Transmission – If Equipped........275
▫Automatic Transmission – If Equipped......276
▫Normal Starting Procedure — Engine Manifold
Airtemperature Above 66°F (19°C).........276
▫Starting Procedure — Engine Manifold Air
Temperature Below 66°F (19°C)...........277
▫Starting Fluids.......................281

Normal Operation (Diesel Engine)...........281▫Cold Weather Precautions...............282
▫Engine Idling — In Cold Weather..........286
▫Stopping The Engine...................287
▫Engine Speed Control..................288
▫Operating Precautions..................288
▫Cooling System Tips —
Automatic Transmission................288

Diesel Exhaust Brake (Engine Braking) –
If Equipped...........................290
5

Transmission Shifting....................291
▫Automatic Transmission With Overdrive
(68RFE) — If Equipped.................291
▫Automatic Transmission With Overdrive
(48RE) — If Equipped..................297

Manual Transmission....................303
▫Recommended Vehicle Shift Speeds........304
▫Downshifting........................305

Four-Wheel- Drive Operation — If Equipped . . . 306
▫Manually Shifted Transfer Case Operating
Information/Precautions................306
▫Shifting Procedure - Manually Shifted
Transfer Case........................308
▫Transfer Case Reminder Light............309▫Electronically Shifted Transfer Case Operating
Information/Precautions–If Equipped.......310
▫Shifting Procedure - Electronically Shifted
Transfer Case........................314

Limited-Slip Differential — If Equipped.......317

Driving On Slippery Surfaces..............318

Driving Off-Road.......................319

Parking Brake.........................320

Brake System..........................321
▫Brake Noise.........................322
▫Four-Wheel Anti-Lock Brake System........322

Power Steering........................324

Tire Safety Information...................325
▫Tire Markings........................325
272 STARTING AND OPERATING